"About 90% of women with hair loss are not strong candidates for hair transplantation surgery because of insufficient donor hair," Angela M. Christiano, PhD, of Columbia University in New York City, said in a statement. "This method offers the possibility of inducing large numbers of hair follicles or rejuvenating existing hair follicles, starting with cell growth from just a few hundred donor hairs.

"It could make hair transplantation available to individuals with a limited number of follicles, including those with female-pattern hair loss, scarring alopecia, and hair loss due to burns."

The study follows previous investigations that demonstrated rapid hair growth after transplantation of cultured rodent papillae onto mice. Investigators hypothesized that human dermal papillae also could be induced to generate new hair follicles. Gene-expression analysis showed that the three-dimensional cultures used in the experiments restored 22% of normal gene expression, less than expected but sufficient to cause hair growth.

In a second cell assay and animal model study, the investigational agent PF-06463922 blocked all known ALK-gene resistance mutations to crizotinib (Xalkori) and passed through the blood-brain barrier to reach brain metastases.

Exercise during pregnancy may influence cardiovascular risk in offspring into adulthood, a study in pigs suggested.

In the study – published in Experimental Physiology – pregnant swine exercised on a treadmill for 20 to 45 minutes, 5 days a week – consistent with recommendations from the American Congress of Obstetricians and Gynecologists and the CDC -- up to 1 week before delivery.

Researchers led by Sean Newcomer, PhD, of California State University San Marcos, then examined vascular function in the femoral arteries of the offspring and found beneficial changes in the vascular smooth muscle.

"Overall, this study is the first to report that gestational exercise is a potent stimulus for programming vascular smooth muscle relaxation in the femoral arteries of adult offspring," the authors wrote.

The bark scorpion, common to the southwestern U.S., uses a painful and sometimes deadly venom to deter predators -- except for the grasshopper mouse, which can shrug off the sting and chow down on the bug. Now researchers led by Ashlee Rowe, PhD, of Michigan State University in East Lansing, have found out why.

In the Oct. 25 issue of Science, they note that the venom causes pain in other mammals by activating the voltage gated sodium channel Nav1.7. Genetic analysis of the grasshopper mice showed that a related sodium channel, Nav1.8, has a unique sequence that -- unlike in other species -- binds the toxin without causing pain. In other words, the nontarget sodium channel essentially acts as an analgesic, preventing activation of the pain-causing channel.

Aside from the rarity and scientific interest of the phenomenon -- almost no other animals can resist prey toxins -- it might also open the door to better analgesics for humans, the researchers conclude.

-- Michael Smith

Tumors Direct Muscle Fiber Repair

Cancer wasting may have more to do with signals from tumors rather than mechanisms related to muscle fibers, a mouse study suggested.

Muscle stem cells – those committed to helping rebuild muscle – were inhibited from doing so in tumor-bearing mice, a response that was associated with the expression of Pax7, according to Denis Guttridge, PhD, of Ohio State University in Columbus, and colleagues.

Researchers found that overexpressing Pax7 in mice with tumors "was sufficient to induce atrophy in normal muscle." Furthermore, reducing Pax7 reversed wasting, they reported in the Journal of Clinical Investigation.

The overexpression of Pax7 is controlled by NF-kappa B (NF-kB); therefore, drugs that target either of these cell factors may be beneficial in controlling cancer wasting, they said.

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